A crack just below the reciever where the clip slides in. My neighbor who used to work in a plastics molding plan told me that it was a defect in the manufacturing process, it was a flow line crack. Although it didnt inhibit performance any, I wasnt about to take my chances and keep the gun any longer when I was able to trade it back in at 80% of the $329 purchase price that I had paid. So I was out $70, it killed me 2 deer and put food on my table. One of the deer was my sons first kill and that is a memory I will never forget. It put teers in my eyes to see the joy in his eyes lol. Now my son is shooting my old 30-30 Marlin and I have the 44 Magnum which is a gun better suited to the terrain that we hunt. Thanks for all the info guys.